The present invention relates to a refrigeration apparatus and, more particularly, to a refrigeration apparatus provided with an air-conditioning heat exchanger and a cooling heat exchanger.
A refrigeration apparatus has been conventionally used widely as an air conditioner for cooling or warming a room, or a cooler for a refrigerant for stocking foods and the like therein. There has also been a refrigeration apparatus for performing both of air-conditioning and freezing, as disclosed in WO 98/45651. The refrigeration apparatus of this type is installed at a place at which both of air-conditioning and freezing are required, for example, at a convenience store or the like, and it is provided with a plurality of compressors and a plurality of heat exchangers on a using side such as an air-conditioning heat exchanger and a refrigerating heat exchanger. Therefore, both of the air-conditioning inside the store and the cooling of a show case or the like can be achieved by the use of the single refrigeration apparatus of this type.
However, in the case where either one of the compressors is broken down in the conventional refrigeration apparatus, there has been a tendency of the degradation of either one of the air-conditioning heat exchanger and the refrigerating heat exchanger or of the entire degradation of both of the heat exchangers.
In view of this, a demand has been increased for a refrigeration apparatus, in which operation can be continued as it is without inducing excessive degradation even if one of the compressors is broken down.
In general, it is more important to maintain the freezing performance than to maintain the air-conditioning performance in the usage requiring both of the air-conditioning and the freezing. This is because the degradation of the air-conditioning performance merely induces an uncomfortable feeling of a resident but the degradation of the freezing performance leads to the degradation of a quality of an object to be cooled (e.g., frozen foods and the like). However, the conventional refrigeration apparatus has not been configured such that the operation is changed so as to secure the freezing performance when the compressor is broken down. Therefore, there has been a demand for a refrigeration apparatus in which the operation can be continued while securing the freezing performance even if one of the compressors is broken down.
The present invention has been accomplished to solve the above-described problems experienced by the prior art. An object of the present invention is to provide a refrigeration apparatus in which operation can be continued as it is even if one of compressors is broken down.
A first refrigeration apparatus comprises: a refrigerant circuit including first, second and third compressors juxtaposed to each other, a heat exchanger on the side of a heat source, an air-conditioning heat exchanger for air-conditioning the inside of a room, cooling heat exchangers for cooling the insides of a refrigerator and a freezer, and a first expanding mechanism and second expanding mechanisms for expanding a refrigerant; and breakdown detecting means for detecting the breakdown of at least the second compressor; the refrigeration apparatus being capable of freely performing at least a cooling operation and a freezing operation, wherein the cooling operation is performed by actuating the second compressor and the third compressor, the cooling operation being achieved by condensing a refrigerant discharged from the second compressor and the third compressor by means of the heat exchanger on the side of the heat source, expanding it by the first expanding mechanism, evaporating it by the air-conditioning heat exchanger, and returning it to the second compressor and the third compressor, and further, the freezing operation is performed by actuating the first compressor and the second compressor, the freezing operation being achieved by condensing a refrigerant discharged from the first compressor and the second compressor by means of the heat exchanger on the side of the heat source, expanding it by the second expanding mechanisms, evaporating it by the cooling heat exchangers, and returning it to the first compressor and the second compressor; and the cooling operation being continued by actuating the first compressor in place of the second compressor if the breakdown of the second compressor is detected during the cooling operation.
A second refrigeration apparatus comprises: a refrigerant circuit including first, second and third compressors juxtaposed to each other, a heat exchanger on the side of a heat source, an air-conditioning heat exchanger for air-conditioning the inside of a room, cooling heat exchangers for cooling the insides of a refrigerator and a freezer, and a first expanding mechanism and second expanding mechanisms for expanding a refrigerant; and breakdown detecting means for detecting the breakdown of at least the second compressor; the refrigeration apparatus being capable of freely performing at least a freezing operation and a cooling/freezing operation, wherein the freezing operation is performed by actuating the first compressor and the second compressor, the freezing operation being achieved by condensing a refrigerant discharged from the first compressor and the second compressor by means of the heat exchanger on the side of the heat source, expanding it by the second expanding mechanisms, evaporating it by the cooling heat exchangers, and returning it to the first compressor and the second compressor, and further, the cooling/freezing operation is performed by actuating the first compressor, the second compressor and the third compressor, the cooling/freezing operation being achieved by condensing a refrigerant discharged from the first compressor, the second compressor and the third compressor by means of the heat exchanger on the side of the heat source, reducing the pressure of a part of the condensed refrigerant down to a first low pressure by the first expanding mechanism, evaporating it by the air-conditioning heat exchanger, and returning it to the third compressor while reducing the pressure of the residual condensed refrigerant down to a second low pressure lower than the first low pressure by the second expanding mechanisms, evaporating it by the cooling heat exchangers, and returning it to the first compressor and the second compressor; the refrigerant circuit further including a refrigerant pipeline for introducing the refrigerant from pipelines on the suction sides of the first compressor and the second compressor to a pipeline on the suction side of the third compressor, and channel switching means disposed on the refrigerant pipeline; and the freezing operation being continued by opening the channel switching means, and further, actuating the third compressor in place of the second compressor if the breakdown of the second compressor is detected during the freezing operation.
A third refrigeration apparatus comprises: a refrigerant circuit including first, second and third compressors juxtaposed to each other, a heat exchanger on the side of a heat source, an air-conditioning heat exchanger for air-conditioning the inside of a room, cooling heat exchangers for cooling the insides of a refrigerator and a freezer, and a first expanding mechanism and second expanding mechanisms for expanding a refrigerant; and breakdown detecting means for detecting the breakdown of at least the second compressor; the refrigeration apparatus being capable of freely performing at least a freezing operation and a cooling/freezing operation, wherein the freezing operation is performed by actuating the first compressor and the second compressor, the freezing operation being achieved by condensing a refrigerant discharged from the first compressor and the second compressor by means of the heat exchanger on the side of the heat source, expanding it by the second expanding mechanisms, evaporating it by the cooling heat exchangers, and returning it to the first compressor and the second compressor, and further, the cooling/freezing operation is performed by actuating the first compressor, the second compressor and the third compressor, the cooling/freezing operation being achieved by condensing a refrigerant discharged from the first compressor, the second compressor and the third compressor by means of the heat exchanger on the side of the heat source, reducing the pressure of a part of the condensed refrigerant down to a first low pressure by the first expanding mechanism, evaporating it by the air-conditioning heat exchanger, and returning it to the third compressor while reducing the pressure of the residual condensed refrigerant down to a second low pressure lower than the first low pressure by the second expanding mechanisms, evaporating it by the cooling heat exchangers, and returning it to the first compressor and the second compressor; the refrigerant circuit further including a refrigerant pipeline for introducing the refrigerant from pipelines on the suction sides of the first compressor and the second compressor to a pipeline on the suction side of the third compressor, and channel switching means disposed on the refrigerant pipeline; and the cooling/freezing operation being continued by opening the channel switching means, and further, by condensing the refrigerant discharged from the first compressor and the third compressor by means of the heat exchanger on the side of the beat source, reducing the pressure down to a predetermined pressure lower than the first low pressure by the first expanding mechanism and the second expanding mechanisms, respectively, evaporating it by the air-conditioning heat exchanger and the cooling heat exchangers, and returning it to the first compressor and the third compressor if the breakdown of the second compressor is detected during the cooling/freezing operation.
A fourth refrigeration apparatus comprises: a refrigerant circuit including first, second and third compressors juxtaposed to each other, a heat exchanger on the side of a heat source, an air-conditioning heat exchanger for air-conditioning the inside of a room, cooling heat exchangers for cooling the insides of a refrigerator and a freezer, and a first expanding mechanism and second expanding mechanisms for expanding a refrigerant; and breakdown detecting means for detecting the breakdown of at least the third compressor; the refrigeration apparatus being capable of freely performing at least a freezing operation and a cooling/freezing operation, wherein the freezing operation is performed by actuating the first compressor and the second compressor, the freezing operation being achieved by condensing a refrigerant discharged from the first compressor and the second compressor by means of the heat exchanger on the side of the heat source, expanding it by the second expanding mechanisms, evaporating it by the cooling heat exchangers, and returning it to the first compressor and the second compressor, and further, the cooling/freezing operation is performed by actuating the first compressor, the second compressor and the third compressor, the cooling/freezing operation being achieved by condensing a refrigerant discharged from the first compressor, the second compressor and the third compressor by means of the heat exchanger on the side of the heat source, reducing the pressure of a part of the condensed refrigerant down to a first low pressure by the first expanding mechanism, evaporating it by the air-conditioning heat exchanger, and returning it to the third compressor while reducing the pressure of the residual condensed refrigerant down to a second low pressure lower than the first low pressure by the second expanding mechanisms, evaporating it by the cooling heat exchangers, and returning it to the first compressor and the second compressor; the refrigerant circuit further including a refrigerant pipeline for introducing the refrigerant from a pipeline on the suction side of the third compressor to pipelines on the suction sides of the first compressor and the second compressor, and channel switching means disposed on the refrigerant pipeline; and the cooling/freezing operation being continued by opening the channel switching means, and further, by condensing the refrigerant discharged from the first compressor and the second compressor by means of the heat exchanger on the side of the heat source, reducing the pressure down to a predetermined pressure lower than the first low pressure by the first expanding mechanism and the second expanding mechanisms, respectively, evaporating it by the air-conditioning heat exchanger and the cooling heat exchangers and, and returning it to the first compressor and the second compressor if the breakdown of the third compressor is detected during the cooling/freezing operation.
A fifth refrigeration apparatus comprises: a refrigerant circuit including first, second and third compressors juxtaposed to each other, a heat exchanger on the side of a heat source, an air-conditioning heat exchanger for air-conditioning the inside of a room, cooling heat exchangers for cooling the insides of a refrigerator and a freezer, and a first expanding mechanism and second expanding mechanisms for expanding a refrigerant; and breakdown detecting means for detecting the breakdown of at least the second compressor; the refrigeration apparatus being capable of freely performing at least a warming operation and a freezing operation, wherein the warming operation is performed by actuating the second compressor and the third compressor, the warming operation being achieved by condensing a refrigerant discharged from the second compressor and the third compressor by means of the air-conditioning heat exchanger, expanding it by the first expanding mechanism, evaporating it by the heat exchanger on the side of the heat source, and returning it to the second compressor and the third compressor, and further, the freezing operation is performed by actuating the first compressor and the second compressor, the freezing operation being achieved by condensing a refrigerant discharged from the first compressor and the second compressor by means of the heat exchanger on the side of the heat source, expanding it by the second expanding mechanisms, evaporating it by the cooling heat exchangers, and returning it to the first compressor and the second compressor; and the warming operation being continued by actuating the first compressor in place of the second compressor if the breakdown of the second compressor is detected during the warming operation.
A sixth refrigeration apparatus comprises: a refrigerant circuit including first, second and third compressors juxtaposed to each other, a heat exchanger on the side of a heat source, an air-conditioning heat exchanger for air-conditioning the inside of a room, cooling heat exchangers for cooling the insides of a refrigerator and a freezer, and a first expanding mechanism and second expanding mechanisms and for expanding a refrigerant; and breakdown detecting means for detecting the breakdown of at least the second compressor; the refrigeration apparatus being capable of freely performing at least a warming operation and a warming/freezing operation, wherein the warming operation is performed by actuating the second compressor and the third compressor, the warming operation being achieved by condensing a refrigerant discharged from the second compressor and the third compressor by means of the air-conditioning heat exchanger, expanding it by the first expanding mechanism, evaporating it by the heat exchanger on the side of the heat source, and returning it to the second compressor and the third compressor, and further, the warming/freezing operation is performed by actuating the first compressor and the second compressor, the warming/freezing operation being achieved by condensing a part of a refrigerant discharged from the first compressor and the second compressor by means of the air-conditioning heat exchanger while condensing the residual discharged refrigerant by means of the heat exchanger on the side of the heat source, expanding both of the refrigerants by the second expanding mechanisms, evaporating them by the cooling heat exchangers, and returning them to the first compressor and the second compressor; the refrigerant circuit further including a refrigerant pipeline for introducing the refrigerant from pipelines on the suction sides of the first compressor and the second compressor to a pipeline on the suction side of the third compressor, and channel switching means disposed on the refrigerant pipeline; and the warming/freezing operation being continued by opening the channel switching means, and further, actuating the third compressor in place of the second compressor if the breakdown of the second compressor is detected during the warming/freezing operation.
In a seventh refrigeration apparatus, the cooling heat exchangers include a refrigerating heat exchanger and a freezing heat exchanger; and
the refrigerant circuit is disposed downstream of the freezing heat exchanger, and includes an auxiliary compressor for reducing the pressure of the refrigerant inside of the freezing heat exchanger lower than that of the refrigerant inside of the refrigerating heat exchanger, in any one of the first to sixth refrigeration apparatuses.
An eighth refrigeration apparatus further comprises a bypass (59) passage connected at one end thereof to the discharge side of the auxiliary compressor (53) and at the other end thereof to the suction side of the auxiliary compressor (53), for allowing the refrigerant to flow in such a manner as to bypass the auxiliary compressor (53) if the auxiliary compressor (53) is broken down, in the seventh refrigeration apparatus.
In the first refrigeration apparatus, the first compressor is driven in place of the second compressor if the second compressor is broken down during the cooling operation. A circulating operation is performed such that the refrigerant discharged from the first compressor and the third compressor is condensed by the heat source side heat exchanger, is expanded by the first expanding mechanism, is evaporated by the air-conditioning heat exchanger, and is returned to the first compressor and the third compressor. Thus, the cooling operation can be continued while maintaining the cooling performance.
In the second refrigeration apparatus, the channel switching means is opened, and further, the third compressor is driven if the second compressor is broken down during the freezing operation. A circulating operation is performed such that the refrigerant discharged from the first compressor and the third compressor is condensed by the heat source side heat exchanger, is expanded by the second expanding mechanism, is evaporated by the cooling heat exchanger, and is returned to the first compressor and the third compressor. Thus, the freezing operation can be continued while maintaining the freezing performance.
In the third refrigeration apparatus, the channel switching means is opened if the second compressor is broken down during the cooling/freezing operation. A circulating operation is performed such that the refrigerant discharged from the first compressor and the third compressor is condensed by the heat source side heat exchanger, is reduced in pressure by the first expanding mechanism and the second expanding mechanisms, is evaporated by the air-conditioning heat exchanger and the cooling heat exchanger, respectively, and is returned to the first compressor and the third compressor. Thus, the refrigerant circulating quantity in the cooling heat exchanger can be maintained. In the meantime, the refrigerant circulating quantity in the air-conditioning heat exchanger is reduced. However, since the pressure of the refrigerant in the air-conditioning heat exchanger is reduced, the evaporation temperature of the refrigerant in the air-conditioning heat exchanger is reduced. Consequently, it is possible to suppress the degradation of the cooling performance of the air-conditioning heat exchanger, although the refrigerant circulating quantity is reduced. Thus, the cooling/freezing operation can be continued while maintaining at least the freezing performance.
In the fourth refrigeration apparatus, the channel switching means is opened if the third compressor is broken down during the cooling/freezing operation. A circulating operation is performed such that the refrigerant discharged from the first compressor and the second compressor is condensed by the heat source side heat exchanger, is reduced in pressure by the first expanding mechanism and the second expanding mechanisms, is evaporated by the air-conditioning heat exchanger and the cooling heat exchanger, respectively, and is returned to the first compressor and the second compressor. Thus, the cooling/freezing operation can be continued while maintaining at least the freezing performance, like the above-described third refrigeration apparatus.
In the fifth refrigeration apparatus, the first compressor is driven in place of the second compressor if the second compressor is broken down during the warming operation. A circulating operation is performed such that the refrigerant discharged from the first compressor and the third compressor is condensed by the air-conditioning heat exchanger, is expanded by the first expanding mechanism, is evaporated by the heat source side heat exchanger, and is returned to the first compressor and the third compressor. Thus, the warming operation can be continued while maintaining the warming performance.
In the sixth refrigeration apparatus, the channel switching means is opened, and further, the third compressor is driven if the second compressor is broken down during the warming/freezing operation. A circulating operation is performed such that a part of the refrigerant discharged from the first compressor and the third compressor is condensed by the air-conditioning heat exchanger while the residual discharged refrigerant is condensed by the heat source side heat exchanger, and further, both of the refrigerants are expanded by the second expanding mechanisms, are evaporated by the cooling heat exchangers, and are returned to the first compressor and the third compressor. Thus, the warming/freezing operation can be continued while maintaining at least the freezing performance.
In the seventh refrigeration apparatus, the cooling heat exchanger includes two kinds of heat exchangers (i.e., a refrigerating heat exchanger and a freezing heat exchanger) having different evaporation temperatures, and therefore, an object to be cooled can be cooled at two kinds of cooling temperatures.
In the eighth refrigeration apparatus, the refrigerant can bypass the auxiliary compressor via the bypass passage if the auxiliary compressor is broken down, thereby achieving a smooth circulation of the refrigerant.
As described above, according to the present invention, the predetermined operation can be continued without inducing any excessive degradation of the performance even if one of the compressors is broken down. Thus, it is possible to enhance the reliability of the apparatus.
In particular, the operation can be continued without degrading the cooling performance of the cooling heat -exchanger in the case where the compressor is broken down during an operation in which the inside of a cold store is cooled by the cooling heat exchanger (such as a freezing operation, a cooling/freezing operation or a warming/freezing operation), thus preventing any deterioration of a quality of the object to be cooled.